Typically in a network of devices which must have low power consumption, communicating devices may sleep for long periods and rely on clocks to wake up and communicate with each other during a defined time slot. One solution is to use a sufficiently precise clock at each transmitter and each receiver so that the transmitters and receivers time slots remain aligned. Precise clocks are expensive and also tend to use more power than less precise clocks. Another solution is to specify long enough time slots so that the imprecise clocks can drift relative to each other and still have sufficient time and overlap in the sending and receiving slots to effectively communicate. Wider time slots do not use communication bandwidth in the network very efficiently and receivers use more power with longer time slots because they need to listen longer in the time slots for a transmission.